api for bundlewatch-service store to fetch details file

[benyael15]

Do you want to request a feature or report a bug?
request a feature

What is the current behavior?
no access for the details file created in store for current brunch.

If the current behavior is a bug, please provide the steps to reproduce.

What is the expected behavior?
an api to the store to fetch this file (using same props such as token, repo details and so on

If this is a feature request, what is motivation or use case for changing the behavior?

in this case - until the issue #30 , of hashing the chunks names for master compression will be easy to walk around bu reading the raw data of the file,

Please mention other relevant information such as the browser version, Node.js version, bundlewatch version, and Operating System.